A damper 1 includes a vessel 2; a partitioning member 6 which partitions the interior of the vessel 2 into two accommodation chambers 4 and 5 for accommodating a viscous fluid 3, and which rotates together with the vessel 2 in an R direction and is movable in an axial direction A; a moving force imparting means 7 for imparting to the partitioning member 6 a moving force in an A1 direction by the input of rotation in an R1 direction; a resilient means 8 for resiliently urging the partitioning member 6 in an A2 direction; a through hole 9 for allowing the two accommodation chambers 4 and 5 inside the vessel 2 to communicate with each other; and an allowing/limiting member 10 which allows the viscous fluid 3 accommodated in the two accommodation chambers 4 and 5 in the vessel 2 to flow reciprocally between the two accommodation chambers 4 and 5 through the through hole 9, and which limits the flow of the viscous fluid 3 in the accommodation chamber 4 into the accommodation chamber 5 in the A2 direction through the through hole 9 when the internal pressure of the viscous fluid 3 accommodated in the accommodation chamber 4 in the A1 direction is generated in excess of a fixed value on the basis of the movement of the partitioning member 6 in the A1 direction.